Saturday night I recorded the Warriors on Channel 720
Sunday I got a v52 error
Monday I got a v53 error
I have lost access to 720, 721, 722, 723, 724 and 725
I tried resetting my Tivo and unplugging after receiving the errors. It made no difference.
Nothing changed on Saturday (except the time). So what is going on with these channels?
V52 and V53 are signal quality error codes, often due to poor coax connections, usually in or near your home.
If you want to troubleshoot this yourself, please see Tivo's Troubleshooting Digital TV Signals.
If you can't find the problem or you'd rather have Comcast do the troubleshooting, call them at the phone number on your bill or 1-800-Comcast, or or use one of the options on https://www.xfinity.com/support/contact-us/. If they can't fix the problem remotely, insist they send a tech out to identify the cause and correct it.
If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit unless you have their Service Protection Plan (https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device, or anything outside your home, you shouldn't be charged.